Technical Field
The present disclosure relates to a circuit substrate structure, and more particularly, to a circuit substrate structure having a flattening material layer.
Description of Related Art
FIG. 1 is a sectional view of a traditional circuit substrate structure 100, which includes a substrate 110, a pixel array layer 120, a display unit 130 an integrated circuit chip 140, a flexible printed circuit board 150, a passivation layer 160 and a sealant 170.
In FIG. 1, the pixel array layer 120 is positioned on the substrate 110, and has a display area (not shown) and a non-display area (not shown). The display area 130 is positioned on the display area of the pixel array layer 120. The integrated circuit chip 140 and the flexible printed circuit board 150 are positioned on the non-display area of the pixel array layer 120, and electrically connected to each other through the pixel array layer 120. The passivation layer 160 covers the display unit 130. Then the sealant 170 is infiltrated by capillary action into the space between the passivation layer 160 and the pixel array layer 120, and cured by heating.
However, in a traditional display device, the sealant 170 is originally in liquid form without a fixed shape, so that the surface of the non-display area of the display area is not even. Besides, since the structure of the traditional display device has a difference in height forming several blind angles, the sealant 170 fails to uniformly infiltrate thereinto and thus generate several bubbles 180. The bubbles 180, after the heat-curing step of the sealant 170, are expanded to lift off the passivation layer 160 and the display unit 130, so as to deteriorate the reliability of the display device. Therefore, there is a need for an improved circuit substrate structure and a method of manufacturing the same, so as to solve the problems met in the art.